Space exploration and human survival

I am sympathetic to the view that, given the likelihood of massive natural disasters, such as collisions between the Earth and large asteroids, we should engage in large-scale space exploration and colonization so as to hedge our bets against extinction. I will consider several criticisms of this view. For example, some philosophers may raise objections against the notion of long-term human survival as a value. How can we have obligations towards beings who have not even been conceived yet and thus cannot be properly said to have rights? On a different note, Wendell Berry argues that the abundance of resources in space will produce bad character, for good character requires the discipline of finitude. Others challenge the connection between space exploration and survival, for they fear that by entertaining the promise of new Earths in the heavens we are more likely to neglect our planet, thus leading to our downfall. Presumably, we should instead increase our efforts to restore and preserve the balance of nature. I will advance a variety of replies. For example, we do decide for posterity to a great extent. We may plant the trees from which “our” descendants will receive nourishment and shade, or we may destroy what could have given them a fighting chance against drought and famine. We have an obligation not to plant a bomb that will go off two years from now in a hospital nursery, and another to ensure that the buildup of chemicals in the hospital water tank will not reach critical mass and kill most of the newborns in ten years. The “balance of nature” involved in another objection is a myth that cannot be justified by natural history, whether astronomical or biological. Moreover, the inevitable changes in the environment, independent of asteroid impacts, will make the Earth uninhabitable in a few hundreds of millions and years. In addition, in order to act wisely we need an understanding of the Earth as a planet, and this requires the exploration of space.     

Overview of current capabilities and research and technology developments for planetary protection

The pace of scientific exploration of our solar system provides ever-increasing insights into potentially habitable environments, and associated concerns for their contamination by Earth organisms. Biological and organic-chemical contamination has been extensively considered by the COSPAR Panel on Planetary Protection (PPP) and has resulted in the internationally recognized regulations to which spacefaring nations adhere, and which have been in place for 40 years. The only successful Mars lander missions with system-level “sterilization” were the Viking landers in the 1970s. Since then different cleanliness requirements have been applied to spacecraft based on their destination, mission type, and scientific objectives. The Planetary Protection Subcommittee of the NASA Advisory Council has noted that a strategic Research & Technology Development (R&TD) roadmap would be very beneficial to encourage the timely availability of effective tools and methodologies to implement planetary protection requirements. New research avenues in planetary protection for ambitious future exploration missions can best be served by developing an over-arching program that integrates capability-driven developments with mission-driven implementation efforts. This paper analyzes the current status concerning microbial reduction and cleaning methods, recontamination control and bio-barriers, operational analysis methods, and addresses concepts for human exploration. Crosscutting research and support activities are discussed and a rationale for a Strategic Planetary Protection R&TD Roadmap is outlined. Such a roadmap for planetary protection provides a forum for strategic planning and will help to enable the next phases of solar system exploration.     

基于THz大气窗口的金星地表遥感研究

文章以金星快车VIRTIS载荷相关数据为出发点,验证金星大气模型相适应参数及其窗口。并通过模型参数中的THz频谱分布,阐述实现金星地表遥感探测科学目标的THz相适应理论基础,并提出多功能金星遥感构想。     

European space research in support of international partnership

The envisaged future space research programmes, whether in the field of space exploration or Earth observation are becoming more and more technically complicated and so costly that a single nation can hardly afford to realize them. Major non-European space-faring nations, China and India will progressively play an important role besides US, Russia and Japan. The Space Advisory Group of the European Commission recommended that the European Commission supports within Horizon 2020 a comprehensive Robotic Mars-Exploration Programme under European leadership that should become an essential element of a coordinated international space research programme. The International Space Station (ISS) experience shows that cooperative space programmes build links between industries and laboratories from around the world, which then further develop in non-space related activities, with positive impact on the economy and scientific research. Strategies need to be developed to mitigate the gradual increasing risks incurred by climate change. In order to lower their entry barrier to engage in space emerging and developing space nations need to be included in cooperative space programmes. We present the recommendations of the Space Advisory Group of the European Commission concerning Europe's participation to global space endeavours.     

载人月面着陆及起飞技术初步研究

载人登月任务中最具特色的就是载人月面着陆及起飞过程,其技术体系丰富,是影响载人登月任务成败的关键环节。文章详细分析了载人月面着陆及起飞阶段的飞行方案,阐述了载人任务与无人任务设计准则上的区别,剖析了载人月面着陆及起飞技术的内涵。此外重点分析了低温推进剂蒸发量控制技术、10∶1深度变推力液体发动机技术、发动机推力矢量控制技术、大承载着陆缓冲技术、发动机羽流导流与防护技术、月尘清除及防护技术等六项与载人登月舱推进系统和结构系统相关的关键技术,分析提出了相应的技术途径和解决方案,对深入认识载人登月飞行器系统的技术体系及技术难度具有重要意义。     

“嫦娥二号”卫星CCD立体相机的关键技术

文章介绍了中国两次绕月探测中 CCD 立体相机所采用的技术与创新,并与国际同类相机所获取的图像进行了比较;在此基础上详细介绍了“嫦娥二号”(CE-2)卫星CCD立体相机的综合创新集成技术--“单镜头两视角同轨立体成像、时间延迟积分图像传感器（TDICCD）推扫、速高比补偿”,并从工程目标与科学目标出发进行探测灵敏度及成像动态范围的需求分析;根据需求分析确定了总体技术方案,包括光、机、电的优化设计以及对月探测中首次采用TDICCD的技术困难与对策;特别讨论了速高比补偿的方案及实施途径,并进行了在轨试验验证。文章最后分别给出了虹湾地区成像分辨率为1.3m以及全月面分辨率为7m 的代表性图像,图像清晰、层次丰富,显示出中国在对月立体成像技术上取得了显著进步。     

The essential role of human spaceflight

The question is: should the United States and nations at large pursue a human spaceflight program (and if so, why)? I offer an unwavering positive answer to this question, and state the reasons for it while considering the broad challenges and benefits of (human) spaceflight. Space exploration is a human activity that is intrinsically forward-looking, and as such, has positive potential. Both national and international space programs can galvanize the population, inspire the youth, foster job-creation, and motivate the existing workforce. The nature of the enterprises involved—their scale, novelty, and complexity—requires a steady and continuous upward progression toward greater societal, scientific and technological development. That is, in order to overcome the challenges of human spaceflight, progress is required. More to the point, the survival of humanity depends on expanding beyond the confines of our planet. Human spaceflight, in short, presents us with an opportunity to significantly advance the nation and the global community.     

三体系统中引力拖车的偏置非开普勒轨道研究

为了研究太阳-小行星-引力拖车三体系统中引力拖车的轨道运动问题,采用柱坐标系下的Hill方程描述了三体系统中引力拖车的运动情况,应用平均化方法消除周期项的影响,得到平均偏置非开普勒轨道的表达式,并研究了轨道稳定性与引力拖车最大有效拉力等问题.研究表明:三体系统中,在小行星飞行方向（或反方向）上存在偏置非开普勒轨道;与二...     

A sample collector for robotic sample return missions II: Radiation tests

Sample return from small solar system objects is playing an increasingly important part in solar system exploration. Critical to such missions is a robust, simple, and economic sample collector. We have developed a collector such as this for near-Earth asteroid sample return missions that we have termed the Touch-and-Go Impregnable Pad (TGIP). The collector utilizes a silicone substrate that is pushed into the dust and gravel surface layer of the asteroid. As part of a systematic evaluation of the TGIP, we have investigated the resilience of this substrate to ionizing radiations. Several miniature versions of the collector, containing typically ∼3 g of the collection substrate, were exposed to 0.564 MeV beta particles from a ⁹⁰Sr source and a 6 MeV electron beam in a linear accelerator to simulate the wide range of energies of solar and galactic ionizing radiation. Various radiation levels up to eight times greater than expected on a six-year asteroid mission (in the case of beta radiation) and 50 times greater than expected (in the case of the 6 MeV electron radiation) were administered to the substrate. After irradiation, the efficiency of the substrate in collecting samples of mock regolith was compared with that of collectors that had not been irradiated. No difference beyond experimental uncertainty was observed and we suggest that the operational TGIP will not be affected adversely by radiation doses expected during a typical six-year inner solar system mission.